Quaternary ammonium salts carrying two hydrophobic long chain hydrocarbon moieties have found broad use as an active in fabric enhancer compositions. Methyltriethanolammonium methylsulfate fatty acid diesters and dimethyldiethanolammonium chloride fatty acid diesters are well known softening actives. In U.S. Pat. No. 8,813,199 a new class of quaternary ammonium salts is described; the aqueous fabric-enhancer compositions comprising them are particularly stable at high temperature.
However, there is still a need to discover new fabric-softening providing additional benefit, such as good softening performance, good storage stability and good viscosity in a composition.